Thermal metamaterials for low-power MEMS thermal control

Abstract

To enable efficient passive cooling of components.SOLUTION: A thermal metamaterial device 100 comprises at least one MEMS thermal switch 110, comprising a substrate layer 112 including a first material having a first thermal conductivity, and a thermal bus 114 over a first portion of the substrate layer 112. The thermal bus 114 includes a second material having a second thermal conductivity higher than the first thermal conductivity. An insulator layer is over a second portion of the substrate layer and includes a third material that is different from the first and second materials. A thermal pad 120 is supported by a first portion of the insulator layer, the thermal pad 120 including the second material, and having an overhang portion 122 located over a portion of the thermal bus 114. When a voltage is applied to the thermal pad 120, an electrostatic interaction occurs to cause a deflection of the overhang portion 122 toward the thermal bus 114, thereby providing thermal conductivity between the thermal pad 120 and the thermal bus 114.SELECTED DRAWING: Figure 1A

Description

Background Art

[0001] Many types of micro-electro-mechanical systems (MEMS) sensors and atomic sensors have temperature-dependent errors. For example, for operation over a typical military temperature range of -40°C to 85°C, the error can be minimized by controlling the temperature of the sensor, such as by heating or cooling the sensor.

[0002] Heating can be easily achieved by electrical resistivity, which can be incorporated into a MEMS sensor or atomic sensor by appropriate lithographic patterning of a resistive circuit. Cooling is more difficult to achieve because conventional devices, such as thermoelectric cooling devices, are very inefficient and introduce a strong thermal conductive coupling to the environment, which also reduces the efficiency of the resistive heating element.

Summary of the Invention

[0003] A thermomaterial device includes at least one micro-electro-mechanical systems (MEMS) thermal switch. The MEMS thermal switch includes a substrate layer including a first material having a first thermal conductivity, and a heat bath on a first portion of the substrate layer, the heat bath including a second material having a second thermal conductivity higher than the first thermal conductivity. An insulator layer is on a second portion of the substrate layer, the insulator layer including a third material different from the first and second materials. The insulator layer includes a first portion having a first height and a second portion having a second height less than the first height. A heat pad is supported by the first portion of the insulator layer, the heat pad including the second material and having an overhang portion positioned on a portion of the heat bath. When a voltage is applied to the heat pad, an electrostatic interaction occurs between the heat pad and the heat bath, causing the overhang portion of the heat pad to deflect toward the heat bath, thereby providing thermal conductivity between the heat pad and the heat bath.

Brief Description of the Drawings

[0004] The features of this disclosure will become apparent to those skilled in the art from the following description with reference to the drawings. Understanding that the drawings only illustrate typical embodiments and should therefore not be considered limiting, this embodiment will be described with further specificity and detail using the drawings.

[0005] [Figure 1A] This is a schematic top view of a classification of thermal metamaterials, including a micro-electromechanical system (MEMS) thermal switch, according to one embodiment.

[0006] [Figure 1B] This is a schematic side view of the thermal metamaterial section of Figure 1A, including the MEMS thermal switch. [Figure 1C] This is a schematic side view of the thermal metamaterial section of Figure 1A, including the MEMS thermal switch.

[0007] [Figure 2] A is a schematic top view of a thermal metamaterial having an array of MEMS thermal switches according to one embodiment. B is a schematic bottom view of the thermal metamaterial of Figure 2A. C is an enlarged top view of a section of the thermal metamaterial of Figure 2A.

[0008] [Figure 3A] This is a schematic side view of a method for fabricating MEMS devices, including thermal metamaterials, using an exemplary approach. [Figure 3B] This is a schematic side view of a method for fabricating MEMS devices, including thermal metamaterials, using an exemplary approach. [Figure 3C] This is a schematic side view of a method for fabricating MEMS devices, including thermal metamaterials, using an exemplary approach. [Figure 3D] This is a schematic side view of a method for fabricating MEMS devices, including thermal metamaterials, using an exemplary approach. [Figure 3E] This is a schematic side view of a method for fabricating MEMS devices, including thermal metamaterials, using an exemplary approach. [Figure 3F] This is a schematic side view of a method for fabricating MEMS devices, including thermal metamaterials, using an exemplary approach. [Figure 3G] This is a schematic side view of a method for fabricating MEMS devices, including thermal metamaterials, using an exemplary approach. [Figure 3H] This is a schematic side view of a method for fabricating MEMS devices, including thermal metamaterials, using an exemplary approach. [Figure 3I] This is a schematic side view of a method for fabricating MEMS devices, including thermal metamaterials, using an exemplary approach. [Figure 3J] This is a schematic side view of a method for fabricating MEMS devices, including thermal metamaterials, using an exemplary approach. [Figure 3K] This is a schematic side view of a method for fabricating MEMS devices, including thermal metamaterials, using an exemplary approach.

[0009] [Figure 4] An exemplary embodiment illustrates a thermal isolation scaffold that can be implemented using a thermal metamaterial.

[0010] [Figure 5] This is a block diagram of a variable temperature control system that provides variable thermal conductivity to a thermal metamaterial, according to an exemplary embodiment. [Modes for carrying out the invention]

[0011] The following detailed description refers to the accompanying drawings illustrating various exemplary embodiments. It should be understood that other embodiments may be available; therefore, the following detailed description should not be interpreted as restrictive.

[0012] Thermal metamaterials for low-power microelectromechanical system (MEMS) thermal control are described herein. The thermal metamaterials can be implemented to have variable thermal conductivity in various embodiments.

[0013] This approach incorporates a number of thermal switches that can be actuated by various possible mechanisms (e.g., electrostatic, piezoelectric, thermal bimorph, and the like) to reduce the effective thermal conductivity of the material through which a MEMS sensor or atomic sensor is heat-sinked. This provides efficient cooling when the ambient temperature is high without sacrificing efficient heating ability when the ambient temperature is low. In some cases, such as for use in a chip-scale atomic clock, this approach can be incorporated into existing manufacturing process flows with only minor additional changes, resulting in benefits at minimal additional cost.

[0014] The device provides a thermal conductivity coefficient that is orders of magnitude greater than conventional approaches by stabilizing the temperature of various electronic components. Due to their internal heat loads, these electronic components need to be actively or passively cooled to operate at high ambient temperatures. This approach enables efficient passive cooling of such components.

[0015] In one embodiment, the thermal metamaterial is based on a metal cantilever that can be actuated by one of several possible mechanisms. In one implementation, the thermal metamaterial can be lithographically patterned onto an existing support structure for a MEMS device such as a chip-scale atomic clock, and the small components are supported on a small thermally isolated platform (i.e., a scaffold). For example, these components can be manufactured in a batch process from a wafer (e.g., a silicon wafer) with hundreds of scaffolds per wafer incorporating the thermal metamaterial device.

[0016] Further details of various embodiments are described below with reference to the drawings.

[0017] Figures 1A - 1C illustrate different views of a section of a metamaterial 100 that includes at least one MEMS thermal switch 110, according to one embodiment. The MEMS thermal switch 110 can be implemented as an array of thermal switches within the metamaterial 100, as further described below. The metamaterial 100 can be formed on a thermally isolated platform, such as a scaffold, that is thermally isolated from the ambient environment, as further described below.

[0018] The MEMS thermal switch 110 includes a substrate layer 112 that includes a first material having a first thermal conductivity. For example, the first material can be a lower thermal conductivity material such as polyimide, porous silicon, glass, combinations thereof, or the like.

[0019] A heat bus 114 is formed on a first portion of the substrate layer 112 and can be connected to ground. The heat bus 114 includes a second material having a second thermal conductivity that is higher than the first thermal conductivity. For example, the second material can be a metal such as copper, gold, aluminum, combinations thereof, or the like.

[0020] An insulator layer 116 (FIGS. 1B and 1C) is formed on a second portion of the substrate layer 112. The insulator layer 116 includes a first portion 117 having a first height (e.g., a mesa portion) and a second portion 118 having a second height that is less than the first height. The insulator layer 116 includes a third material that is different from the first and second materials. For example, the third material can be an oxide or nitride material such as silicon dioxide, silicon nitride, combinations thereof, or the like.

[0021] A heat pad 120 is supported by the first portion 117 of the insulator layer 116. The heat pad 120 includes the second material having a higher thermal conductivity and has an overhang portion 122. The overhang portion 122 is positioned over a portion of the heat bus 114.

[0022] A voltage source 124 (Figures 1B and 1C) is electrically coupled to the heating pad 120, for example, through one or more metal contacts 126. A pair of support sections 128 are coupled onto the heating pad 120, with the support sections 128 containing a first material having lower thermal conductivity. The metal contacts 126 are coupled to the support sections 128.

[0023] As shown in Figure 1B, when the voltage is zero, the protruding portion 122 of the thermal pad 120 remains unbent toward the thermal bath 114. This provides low thermal conductivity between the thermal pad 120 and the thermal bath 114. As shown in Figure 1C, when the voltage applied to the thermal pad 114 is greater than zero, the protruding portion 122 is deflected toward the thermal bath 114 due to the electrostatic interaction that occurs between the thermal pad 120 and the thermal bath 114. This provides high thermal conductivity between the thermal pad 120 and the thermal bath 114.

[0024] In one embodiment, the voltage control of the voltage source 124 may be unipolar (+V to ground). In another embodiment, the voltage control may be bipolar (+V to -V). In alternative embodiments, further described below, variable temperature control may be provided by using pulse width modulation (PWM). Using PWM allows for intermittent connections and provides continuous adjustment of the thermal conductivity of the thermal metamaterial.

[0025] Figures 2A and 2B illustrate, respectively, a top view and a bottom view of a thermal metamaterial 200 having an array of MEMS thermal switches 210, according to an exemplary embodiment. The thermal metamaterial 200 may be formed on a thermally isolated platform 202, such as scaffolding, so that the thermal metamaterial 200 is thermally isolated from the surrounding environment.

[0026] Figure 2C is an enlarged top view of a section of the thermal metamaterial 200 illustrating one of the MEMS thermal switches 210. Each of the MEMS thermal switches 210 has a structure similar to that of the MEMS thermal switch 110 described above. Therefore, each MEMS thermal switch 210 includes a substrate layer 212 containing a first material having lower thermal conductivity, such as polyimide.

[0027] The thermal bath 214 is formed on a first portion of the substrate layer 212 and can be connected to ground. The thermal bath 214 contains a second material having higher thermal conductivity, such as copper.

[0028] The insulating layer is formed on a second portion of a substrate layer 212, such as an insulating layer 116 (Figures 1B and 1C), which includes a first portion 117 having a first height and a second portion 118 having a second height less than the first height. The insulating layer includes a third material different from the first and second materials. For example, the third material may be silicon dioxide.

[0029] The thermal pad 220 is supported by a first portion of an insulating layer. The thermal pad 220 comprises a second material having higher thermal conductivity (e.g., copper) and has an overhang portion 222. The overhang portion 222 is positioned above a portion of the thermal bath 214.

[0030] A voltage source is electrically coupled to the heating pad 220, for example, through one or more metal contacts 226, such as copper contacts. A pair of support sections 228 are coupled onto the heating pad 220, with the support sections 228 containing a first material having lower thermal conductivity (e.g., polyimide). The metal contacts 226 are coupled to the support sections 228.

[0031] The MEMS thermal switch 210 operates in the same manner as the MEMS thermal switch 110 described above. Therefore, when the voltage is zero, the protruding portion 222 of the thermal pad 220 remains unbent toward the thermal bath 214. This provides low thermal conductivity between the thermal pad 220 and the thermal bath 214. When the voltage applied to the thermal pad 214 is greater than zero, the protruding portion 222 is deflected toward the thermal bath 214, providing high thermal conductivity between the thermal pad 220 and the thermal bath 214.

[0032] As further described below, variable temperature control can be provided by using a PWM process, which allows intermittent connections to provide continuous adjustment of the thermal conductivity of the thermal metamaterial 200.

[0033] Figures 3A to 3K illustrate schematic side views of a method for manufacturing a MEMS device, including the thermal metamaterial described above, using an exemplary approach. First, a substrate layer 302, such as a wafer, made of a material with higher thermal conductivity, such as silicon, is provided, as shown in Figure 3A. A first polymer layer 304 is formed on the substrate layer 302. The first polymer layer 304 is made of a material with lower thermal conductivity, such as polyimide. As shown in Figure 3B, the substrate layer 302 is etched to produce island portions 306 that are crosslinked by the first polymer layer 304. In one embodiment, the substrate layer 302, the island portions 306, and the first polymer layer 304 can be formed as part of a thermal isolation scaffold.

[0034] As shown in Figure 3C, the first metal layer 308 is deposited on the first polymer layer 304 by an electron beam (e-beam) or sputtering process, for example. The first metal layer 308 may consist of, for example, copper, gold, or aluminum. The first metal layer 308 is then patterned by a wet etching or ionic grinding process, for example, to produce a hot bath portion 310 that protrudes from the first polymer layer 304, as shown in Figure 3D.

[0035] Subsequently, as illustrated in Figure 3E, the insulating layer 312 is formed on the hot bath portion 310 and the exposed portion of the first polymer layer 304 by chemical vapor deposition (CVD) or a sputtering process, for example. The insulating layer 312 can be made of, for example, silicon dioxide or silicon nitride. Then, a second metal layer 314 (e.g., copper or gold) is deposited on the insulating layer 312 by e-beam or a sputtering process, for example. The second metal layer 314 is then patterned by wet etching or an ionic grinding process, for example, as shown in Figure 3F, to produce a set of electrode pads 316 protruding from the insulating layer 312.

[0036] As shown in Figure 3G, the insulating layer 312 is partially etched in preparation for the formation of the upper electrical contacts, exposing the upper surface portion of the first polymer layer 304. As shown in Figure 3H, the second polymer layer 318 (e.g., polyimide) is formed on the exposed surface portion, including the electrode pad 316, the insulating layer 312, and the first polymer layer 304, by a spinning process, etc.

[0037] Next, as shown in Figure 3I, the second polymer layer 318 on the electrode pad 316 is etched, and a third metal layer 320 (e.g., copper or gold) is deposited on the second polymer layer 318 to form a pair of upper contacts 322. As shown in Figure 3J, the third metal layer 320 is etched together with the portion of the second polymer layer 318 to form an upper metal grid pattern 324. Then, as illustrated in Figure 3K, the insulating layer 312 is partially etched, such as by wet etching, to remove the area beneath the electrode pad 316, generating a pair of thermal pads 326 supported by the raised portion of the insulating layer 312.

[0038] Subsequently, upper polymer layers, such as polyimide layers, can be optionally formed on the thermal metamaterial manufacturing structure by processes such as spinning. The aforementioned methods can be used in batch manufacturing processes to produce thermal metamaterials.

[0039] As mentioned above, thermal metamaterials can be formed on support structures for small devices such as chip-scale atomic clocks, where the small components are supported on small, thermally isolated scaffolds. These structures can be manufactured in a batch process from wafers, with hundreds of scaffolds per wafer incorporating the thermal metamaterial.

[0040] Figure 4 illustrates an example of such a thermal isolation scaffold 400, which can be implemented with a thermal metamaterial, according to one embodiment. The thermal isolation scaffold 400 includes a substrate 402, such as a silicon substrate, and island portions 404, such as silicon islands, which are thermally isolated from and surrounded by the substrate 402. An integrated heater coil 406 is positioned on the island portion 404. A pair of tethers 410, such as polyimide tethers having low thermal conductivity, connect the substrate 402 to the island portion 404. The tethers 410 thermally isolate the island portion 404 from the substrate 402. As shown in Figure 4, the thermal metamaterial 414 is formed on at least one of the tethers 410.

[0041] The island portion 404 may also house a temperature sensor for feedback control of the heater coil 406. Alternatively, the temperature may be controlled by other mechanisms, such as by the temperature response of other components (e.g., a miniature laser or atomic gas cell).

[0042] As described above, the thermal metamaterial can be implemented to have variable thermal conductivity in various embodiments. Figure 5 illustrates a variable temperature control system 500 operably coupled to a thermal isolation scaffold 510. The thermal isolation scaffold 510 includes a thermal reservoir 512 such as a silicon substrate and a thermal metamaterial 514, and a thermal control region 516 such as a silicon island containing an integrated heater coil. The variable temperature control system 500 is configured to provide adjustment of the thermal conductivity of the thermal metamaterial 514.

[0043] The variable temperature control system 500 includes a processor unit 502, such as a proportional-integral-derivative (PID) controller, which outputs a feedback signal, such as a PWM signal. A thermal sensor 504 is configured to measure the actual temperature of the thermal control region 516. A temperature setpoint unit 506 is configured to provide a desired temperature setpoint for the thermal metamaterial 514. A subtraction circuit 508, coupled to the processor unit 502, is configured to receive temperature values ​​from the thermal sensor 504 and the setpoint unit 506.

[0044] During operation, the subtraction circuit 508 compares the temperature value from the setpoint unit 506 with the actual temperature value from the thermal sensor 504. The subtraction circuit 508 outputs the differential temperature value to the processor unit 502, which outputs a feedback signal (PWM signal) based on the differential temperature value. The feedback signal is sent to the thermal metamaterial 514, or to both the metamaterial 514 and the integrated heater coil. The feedback signal enables intermittent connection, providing continuous adjustment of the thermal conductivity of the thermal metamaterial 514. Exemplary Embodiments

[0045] Example 1 includes a device comprising at least one micro-electromechanical system (MEMS) thermal switch, comprising: a substrate layer comprising a first material having a first thermal conductivity; a thermal bath on a first portion of the substrate layer, wherein the thermal bath comprises a second material having a second thermal conductivity higher than the first thermal conductivity; an insulating layer on a second portion of the substrate layer, wherein the insulating layer comprises a third material different from the first and second materials, and the insulating layer comprises a first portion having a first height and a second portion having a second height less than the first height; and a thermal pad supported by the first portion of the insulating layer, wherein the thermal pad comprises a second material and has an overhang portion, the overhang portion being positioned on a portion of the thermal bath, and when a voltage is applied to the thermal pad, an electrostatic interaction occurs between the thermal pad and the thermal bath, causing the overhang portion of the thermal pad to deflect toward the thermal bath, thereby providing thermal conductivity between the thermal pad and the thermal bath.

[0046] Example 2 includes the device of Example 1, wherein the first material includes polyimide, porous silicon, glass, or a combination thereof.

[0047] Example 3 comprises one of the devices from Examples 1 or 2, wherein the second material is a metal including copper, gold, aluminum, or a combination thereof.

[0048] Example 4 includes any of the devices from Examples 1 to 3, wherein the third material includes silicon dioxide, silicon nitride, or a combination thereof.

[0049] Example 5 includes any of the devices from Examples 1 to 4, and further comprises a voltage source electrically coupled to the heating pad through one or more metal contacts.

[0050] Example 6 includes the device of Example 5, further comprising a pair of support sections bonded to a thermal pad, the support sections comprising a first material, and metal contacts bonded to the support sections.

[0051] Example 7 comprises any device from Examples 1 to 6, further comprising a scaffold supporting at least one MEMS thermal switch, the scaffold being thermally isolated from the surrounding environment.

[0052] Embodiment 8 includes the device of Embodiment 7, wherein the scaffold comprises a substrate, an island portion thermally isolated from and surrounded by the substrate, an integrated heater coil positioned on the island portion, and a pair of tethers connecting the substrate to the island portion, the tethers being configured to thermally isolate the island portion from the substrate.

[0053] Example 9 includes the device of Example 8, wherein at least one MEMS thermal switch is positioned on at least one of the tethers.

[0054] Example 10 includes any of the devices from Examples 8 to 9, wherein the substrate and island portions are made of silicon, and the tether is made of polyimide.

[0055] Example 11 is a metamaterial comprising a microelectromechanical system (MEMS) device, comprising a thermal isolation scaffold and an array of MEMS thermal switches on the thermal isolation scaffold, each of which comprises a substrate layer comprising a first material having a first thermal conductivity, a thermal bath on a first portion of the substrate layer, wherein the thermal bath comprises a second material having a second thermal conductivity higher than the first thermal conductivity, and an insulating layer on a second portion of the substrate layer, wherein the insulating layer comprises a third material different from the first and second materials, and the insulating layer comprises a first portion having a first height and a second portion having a second height less than the first height A metamaterial comprising an insulating layer including a second portion, a thermal pad supported by the first portion of the insulating layer, wherein the thermal pad comprises a second material and has an overhang portion, the overhang portion being positioned on a portion of a heat bath, and a voltage source electrically coupled to each thermal pad of each MEMS thermal switch, wherein when a voltage is applied from the voltage source, electrostatic interactions occur within the MEMS thermal switch between each thermal pad and each heat bath, causing the overhang portion of the thermal pad to deflect toward the heat bath, thereby providing thermal conductivity between the thermal pad and the heat bath.

[0056] Example 12 includes the MEMS device of Example 11, wherein the thermal isolation scaffold comprises a substrate, an island portion thermally isolated from and surrounded by the substrate, an integrated heater coil positioned on the island portion, and a set of tethers connecting the substrate to the island portion, the tethers being configured to thermally isolate the island portion from the substrate.

[0057] Example 13 includes the MEMS device of Example 12, wherein the array of MEMS thermal switches is positioned on at least one of the tethers.

[0058] Example 14 includes any of the MEMS devices from Examples 12 to 13, wherein the first material includes polyimide, porous silicon, glass, or a combination thereof; the second material includes copper, gold, aluminum, or a combination thereof; and the third material includes silicon dioxide, silicon nitride, or a combination thereof.

[0059] Example 15 includes any MEMS device from Examples 12 to 14, further comprising a variable temperature control system operably coupled to a metamaterial, the variable temperature control system configured to provide variable thermal conductivity of the metamaterial.

[0060] Example 16 includes the MEMS device of Example 15, wherein the variable temperature control system comprises a processor unit operably coupled to a metamaterial; a thermal sensor operably coupled to the metamaterial, configured to measure the actual temperature of the metamaterial; a temperature setpoint unit configured to provide a desired temperature setpoint for the metamaterial; and a subtraction circuit operably coupled to the processor unit, configured to receive temperature values ​​from the thermal sensor and the temperature setpoint unit, respectively, wherein the subtraction circuit is operable to compare the temperature values ​​from the thermal sensor and the temperature setpoint unit and to output a differential temperature value to the processor unit, the processor unit is operable to output feedback to the metamaterial or to both the metamaterial and an integrated heater coil based on the differential temperature value, the feedback signal is operable to enable intermittent connection and provide continuous adjustment of the thermal conductivity of the metamaterial.

[0061] Example 17 includes the MEMS device of Example 16, and the processor unit comprises a proportional-integral-derivative (PID) controller that can be operated to output the feedback signal as a pulse-width modulation (PWM) signal.

[0062] Example 18 includes a method for manufacturing a microelectromechanical system (MEMS) device containing a thermal metamaterial, the method comprising: providing a substrate layer; forming a first polymer layer on the substrate layer; etching the substrate layer to form one or more substrate island portions crosslinked by the first polymer layer; depositing a first metal layer on the first polymer layer; patterning the first metal layer to generate a thermal bath protruding from the first polymer layer; depositing an insulating layer on the thermal bath and the exposed portions of the first polymer layer; depositing a second metal layer on the insulating layer; patterning the second metal layer to generate a pair of electrode pads protruding from the insulating layer; and partially modifying the insulating layer. The process includes etching the first polymer layer to expose the upper surface portion while leaving the remaining portion of the insulating layer around the electrode pad; forming a second polymer layer on the electrode pad, the remaining portion of the insulating layer, and the first polymer layer; etching the second polymer layer on the electrode pad; depositing a third metal layer on the second polymer layer and the electrode pad to form a pair of upper contacts; etching the third metal layer along the portion of the second polymer layer to form an upper metal grid pattern; and partially etching the remaining portion of the insulating layer to remove the area beneath the electrode pad and generate a pair of thermal pads separated from the heat bath.

[0063] Example 19 comprises the method of Example 18, wherein the substrate layer comprises silicon, the polymer layer comprises polyimide, the metal layer comprises copper, gold, aluminum, or a combination thereof, and the insulating layer comprises silicon dioxide, silicon nitride, or a combination thereof.

[0064] Example 20 comprises any method of Examples 18 to 19, wherein the substrate layer, island portion, and first polymer layer are formed as part of a thermal isolation scaffold.

[0065] From the above, specific embodiments have been described for illustrative purposes, but it will be understood that various modifications can be made without departing from the scope of this disclosure. Therefore, the embodiments described should be considered in all respects to be illustrative only and not limiting. Furthermore, all modifications within the meaning and equivalent scope of the claims shall be encompassed within those scopes.

Claims

1. It is a device, A thermal switch comprising at least one micro-electromechanical system (MEMS), A substrate layer comprising a first material having first thermal conductivity, A heat bath on a first portion of the substrate layer, wherein the heat bath includes a second material having a second thermal conductivity higher than the first thermal conductivity, An insulating layer on a second portion of the substrate layer, wherein the insulating layer comprises a third material different from the first and second materials, and the insulating layer comprises a first portion having a first height and a second portion having a second height less than the first height, A micro-electromechanical system (MEMS) thermal switch comprises at least one thermal pad supported by the first portion of the insulating layer, wherein the thermal pad includes the second material and has an overhang portion, the overhang portion being positioned on a portion of the heat bath, A device wherein, when a voltage is applied to the heating pad, an electrostatic interaction occurs between the heating pad and the heating bath, causing the protruding portion of the heating pad to deflect toward the heating bath, thereby providing thermal conductivity between the heating pad and the heating bath.

2. Microelectromechanical Systems (MEMS) devices, Thermal isolation scaffolding, A metamaterial comprising an array of MEMS thermal switches on the thermal isolation scaffold, wherein each of the MEMS thermal switches is A substrate layer comprising a first material having first thermal conductivity, A heat bath on a first portion of the substrate layer, wherein the heat bath includes a second material having a second thermal conductivity higher than the first thermal conductivity, An insulating layer on a second portion of the substrate layer, wherein the insulating layer comprises a third material different from the first and second materials, and the insulating layer comprises a first portion having a first height and a second portion having a second height less than the first height, A metamaterial comprising: a thermal pad supported by the first portion of the insulating layer, wherein the thermal pad includes the second material and has an overhang portion, the overhang portion being positioned on a portion of the heat bath; The MEMS thermal switch comprises a voltage source electrically coupled to each thermal pad of the MEMS thermal switch, A micro-electromechanical system (MEMS) device in which, when a voltage is applied from the voltage source, electrostatic interactions occur between each thermal pad and each thermal bath within the MEMS thermal switch, causing the protruding portion of the thermal pad to deflect toward the thermal bath, thereby providing thermal conductivity between the thermal pad and the thermal bath.

3. A method for manufacturing a micro-electromechanical system (MEMS) device containing a thermal metamaterial, To provide a substrate layer, Forming a first polymer layer on the substrate layer, The substrate layer is etched to form one or more substrate island portions that are crosslinked by the first polymer layer, Depositing a first metal layer on the first polymer layer, The first metal layer is patterned to generate a heat bath that protrudes from the first polymer layer, Depositing an insulating layer on the exposed portion of the heat bath and the first polymer layer, A second metal layer is deposited on the aforementioned insulating layer, Patterning the second metal layer to generate a set of electrode pads protruding from the insulating layer, The insulating layer is partially etched to expose the upper surface portion of the first polymer layer, while leaving the remaining portion of the insulating layer around the electrode pad. A second polymer layer is formed on the electrode pad, the remaining portion of the insulating layer, and the first polymer layer. Etching the second polymer layer on the electrode pad, A third metal layer is deposited on the second polymer layer and the electrode pad to form a set of upper contacts. The third metal layer is etched along the portion of the second polymer layer to form an upper metal grid pattern, A method comprising partially etching the remaining portion of the insulating layer to remove the area beneath the electrode pad and thereby generate a set of thermal pads separated from the heat bath.

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